Burner for a kiln

Claim 2

A burner for a kiln comprising a first duct for conveying an air flow, said first duct having an annular outlet at a terminal end directed in a diverging direction to expel the air flow in a radially outward direction; swirl means at said outlet of said duct for imparting a swirling effect to the expelled air flow; a second duct concentric to and about said first duct for conveying a flow of pulverized coal, said second duct having an outlet at one end to expel the pulverized coal into a flame; a third duct concentric to and about said first and second ducts for conveying an air flow, said third duct having an outlet concentric to and about said first duct outlet for expelling an air flow with an axial component; and means for adjusting the air flows in said first and third ducts to adjust the shape of the flame extending from said second duct between an elongated shape and a flared conical shape.

Claim 3

A burner as set forth in claim 1 wherein said means includes a first valve for controlling the air flow in said first duct and a second valve for controlling the air flow in said third duct.

Claim 4

A burner as set forth in claim 1 which further comprises a connection piece connected in common to each of said first and third ducts to deliver air thereto.

Claim 5

A burner as set forth in claim 3 wherein said means includes a first valve between said connection piece and said first duct to control the flow of air in said first duct and a second valve between said connection piece and said third duct to control the flow of air in said third duct.

Claim 6

A burner as set forth in claim 1 which further comprises a pipe centrally of said first duct for housing at least one conduit for conveying a fuel therethrough, said conduit having an outlet to expel the fuel at said one end of said first duct.

Claim 7

In a powdered coal burner first means for supplying supply air in a generally axial direction, second means for supplying a powdered coal-carrier gas mixture at a constant minimum velocity concentrically within the supplied supply air, third means for supplying air concentrically within the powdered coal carrier gas mixture and in a generally radial direction relative to said generally axial direction of said first means, said first, second and third means including concentric ducts with said first means being the outermost duct with an outlet to expel air with an axial component, the third means being the innermost duct having an annular outlet at a terminal end directed in a diverging direction to expel the air flow in a radially outward direction, and said second means being located between said first and third means, means for adjusting the flame form produced by combusting the powdered coal mixture supplied by said second means without altering the velocity or direction of the powdered coal carrier gas mixture, said adjusting means including means for regulating the quantity of air entered into said first and third supply means; and swirl means for imparting a rotational component to the air supplied by said third means.

Claim 8

In a powdered coal burner first means for supplying supply air in a generally axial direction, second means for supplying a powdered coal-carrier gas mixture at a constant minimum velocity concentrically within the supplied supply air, third means for supplying air concentrically within the powdered coal carrier gas mixture and in a generally radial direction relative to said generally axial direction of said first means, said first, second and third means including concentric ducts with said first means being the outermost duct with an outlet to expel air with an axial component, the third means being the innermost duct having an annular outlet at a terminal end directed in a diverging direction to expel the air flow in a radially outward direction, and said second means being located between said first and third means, means for adjusting the flame form produced by combusting the powdered coal mixture supplied by said second means without altering the velocity or direction of the powdered coal carrier gas mixture, said adjusting means including means for regulating the quantity of air entered into said first and third supply means; and swirl means for imparting a rotational component to the air supplied by said third means.

Claim 9

In a burner as set forth in claim 6, a second swirl means located in said second supply means for mixing the powdered coal carrier gas mixture.

Claim 10

In a burner as set forth in claim 6, a fuel supply means located centrally and radially inwardly of said third supply means.

Claim 11

In a burner as set forth in claim 6 wherein said first supply means includes an inner and outer wall and which further comprises means for moving said outer wall relative to said inner wall.

Claim 12

In a burner as set forth in claim 6 wherein said third supply means includes a first and a second wall and which further comprises means for moving said first and second walls relative to each other.

Claim 13

In combination with a kiln defining a combustion zone; a burner at one end of said zone for introducing a flame into said zone, said burner comprising a first duct for introducing pulverized coal into said zone at a given supply rate to generate a flame within said zone to extend from said end of said zone, and means for adjusting the shape of the flame within said zone between an elongated shape and a flared conical shape without altering said supply rate of pulverized coal, said means including a second duct for conveying an air flow concentrically within said first duct and a third duct for conveying an air flow concentrically about said first duct, said second duct having an annular outlet directed in a diverging direction to expel the air flow in a radially outward direction and said third duct having an outlet to expel an air flow with an axial component.

Claim 14

In combination with a kiln defining a combustion zone; a burner at one end of said zone for introducing a flame into said zone, said burner comprising a first duct for introducing pulverized coal into said zone at a given supply rate to generate a flame within said zone to extend from said end of said zone, and means for adjusting the shape of the flame within said zone between an elongated shape and a flared conical shape without altering said supply rate of pulverized coal, said means including a second duct for conveying an air flow concentrically within said first duct and a third duct for conveying an air flow concentrically about said first duct, said second duct having an annular outlet directed in a diverging direction to expel the air flow in a radially outward direction and said third duct having an outlet to expel an air flow with an axial component.

Claim 15

The combination as set forth in claim 11 wherein said means further includes swirl means in said second duct for imparting a swirling effect to the expelled air flow and means for adjusting the air flows in said second and third ducts to adjust the shape of the flame extending from said burner.